The man told police that militants had trained him in north Lebanon and that an Islamic State operative in Iraq had taught him via the Internet to make an explosive belt, NNA reported.
A security source said the plot was still at an early stage.
Islamic State, which has a large presence in neighbouring Syria and holds a barren pocket of territory on its border with Lebanon, has attacked Lebanon in the past.
Lebanese security sources also accused the group of carrying out eight suicide bombings in a Lebanese Christian village last summer that killed five people and wounded dozens more.
However, Lebanon has mostly escaped the violence and chaos unleashed by Syria's war, where the Lebanese Hezbollah group has been fighting for President Bashar al-Assad.
Islamic State has attacked Lebanon in the past.
Lebanese authorities have arrested a Lebanese man accused of planning a suicide attack on behalf of Islamic State, state news agency NNA reported on Tuesday.
